Currently, the jbossweb load metrics (i.e. ActiveSessionsLoadMetric, BusyConnectorsLoadMetric, RequestCountLoadMetric, ReceiveTrafficLoadMetric, SendTrafficLoadMetric) use jmx to generate their load values.
This is potentially fragile.
Instead, these load metrics should use org.jboss.mod_cluster.Engine as a load context.

This raises the issue of load value scope. Currently, load is scoped to a server. Really, this should be scoped to an engine. While server:engine is usually a 1:1 relationship, this is technically a 1:N relationship.

Suggested API change:

class LoadMetricSource<C extends LoadContext>
{
  C createContext(Engine engine);
}

Where there exists:

class EngineLoadMetricSource<EngineLoadContext>
{
  public EngineLoadContext createContext(Engine engine)
  {
    return new EngineLoadContext(engine);
  }
}

class EngineLoadContext implements LoadContext
{
  private final Engine engine;
  public EngineLoadContext(Engine engine)
  {
    this.engine = engine;
  }
  public Engine getEngine()
  {
    return this.engine;
  }
  public void close()
  {
    // Nothing to close
  }
}

The various jbossweb load metrics would use this source.